1. Field of the Invention
This invention relates to the art of extracting oil from oil-bearing seeds while retaining free fatty acids, pigments, and phospholipids in the oil freed seed material and specifically deals with high yield rapid low temperature solvent extraction of relatively pure oil from low temperature dried finely ground soybean flour having a low moisture content while retaining phospholipids in the seed material from which lecithin can be easily extracted.
2. Description of the Prior Art
Heretofore, oil-bearing seeds such as soybeans have been formed into flakes and oil has been removed from the flakes by solvent extraction. This procedure extracts undesired free fatty acids, pigments, and phospholipids with the oil. The extracted oil therefore has to be refined and degummed to be edible and substantial amounts of oil are lost during the refining process.
It has now been found that drying of the seeds only to moisture contents around 9-10% under relatively low temperature conditions below 130.degree. C., preferably around 70.degree. C., grinding the dried seeds to a fine flour which loses moisture to the atmosphere to provide a flour of 6% or less moisture content followed by a low temperature rapid solvent extraction of the flour produces a purer oil and a phospholipid rich residual seed flour from which valuable lecithin can be easily recovered.
It would therefore be an improvement in this art to enhance the yield and purity of oil extracted from oil-bearing seeds such as soybeans.
It would be a further improvement in this art to retain phospholipids in the seed material during solvent extraction of oil from the seeds and to alternatively leave valuable lecithin in the seed material as a feed stock or to easily solvent extract the lecithin from the seed material.